| COFFEE
BREWING TECHNIQUES |
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| Coffee is a universal beverage, yet a
good cup of coffee is not available everywhere as a rule.
In our country, though we grow good quality coffee, there
is a certain quantum of the beverage, which is sold under
the name of 'coffee', which is anything but 'coffee',
one sometimes tends to be indifferent to the situation.
Since this is the general picture, a beverage to be continuously
popular, must have the required appeal for consumers. |
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| The accompanying note could help caterers
and institutions serve good coffee and profit by it. The
guidelines by the coffee technology unit of the Central
Food Technological Research Institute (CFTRI) Mysore have
detailed that those who are in charge of coffee preparation
and sales will know enough about good quality coffee and
preparation of a good cup of coffee every time. |
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| It is hoped that the information being
provided would make it easy to prepare high quality coffee
with good aroma, not only for economic reasons, but also
to earn a good reputation. |
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| Coffee is one of the most popular non-alcoholic
beverages. A reputation for an excellent brew increases
the prestige of a fine restaurant and many successful
restaurants have been built around a good cup of coffee. |
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| FACTORS CONTRIBUTING TO GOOD COFFEE |
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1. Brewing Process
2. Quality Of Coffee
3. Quality Of Water
4. Cleanliness Of Brewing Device |
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| METHOD OF BREWING |
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1. Boiling.
2. Filtration Or Drip
3. Percolation
4. Vacuum Percolation
5. Extraction Of "Espresso" Under Pressure. |
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| There are various types of brewing equipment,
which use one or the other of the above methods of coffee
making. The most popular one in our country is the filter
method. |
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| RATIO OF POWDER TO WATER: |
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| Using of appropriate quality of water
to get the desired strength in coffee, for a single extraction
to give normal brew, a ratio of 1 to 20 between the weight
of powder and volume of water is recommended. A double
strength brew is obtained with a ratio of 1 : 10. If the
ratio goes below this, the efficiency of single extraction
goes down. |
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| PROPER EXTRACTION: |
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| It is a common belief that the more the
extract obtained from coffee powder, the better is the
beverage. It is now known that over-extracted coffee is
bitter and contains constituents which affects the taste,
even though the maximum soluble solids extractable from
coffee range between 30 and 35% of the weight of powder.
The extraction of desirable solids is in the range of
20 to 26% that is 3 to 402 per pound of powder or 100
gms to 130 gms per 500 gms. All the water used in the
brewing is not recovered as brew. Every ounce of coffee
powder will retain 2 to 3 Oz of water. |
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| TEMPERATURE OF WATER: |
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| In general, a temperature not less than
2000 F (93.30 C) is essential for extracting the major
desirable constituents of coffee. It is preferable to
pre-warm the vessels before the addition of boiling water.
At a higher temperature and pressure that is above the
boiling point of water. The bitter constituents of coffee
would get extracted. |
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| NATURE OF WATER: |
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| The water should be free from any undesirable
odour. Alkaline and very hard water affects the taste
of coffee. If water is hard, crust formation on the equipment
would pose a problem. |
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| It is known that water softened with zeolites
and containing sodium, instead of calcium, takes a longer
time for percolation through the powder. Chlorinated water
containing excess chlorine affects the taste. |
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| KEEPING QUALITY OF BREW: |
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| The brew is at its best quality when it
is fresh. Periods of storage longer than one hour significantly
deteriorate the aroma. The optimum holding temperature
is between 185 and 190F, without variation. Rapid breakdown
of flavour occurs when the temperature fluctuates and
also in the presence of sediments in the brew. This applies
both to single strength and double strength brews. The
brew should be stored in a closed container so that the
brew does not pick up those foreign odours. |
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| NATURE OF MILK: |
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| For a single strength brew obtained with
a ratio of 1 to 20, the general proportion of milk to
brew is 1:3. Milk with a fat content of not less than
3 to 3.5% is desirable. Poor quality milk affects the
taste. A general improvement in taste however, could be
obtained by the use of buffalo milk, with a higher fat
content. |
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| SUGAR: |
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| 7.5% gms of sugar per every 100 cc (3
½ OZ) is required for average taste. The sugar
should be fairly pure and free from foreign taste. The
taste for coffee varies with individuals and general acceptability
is between 0.75 to 1.3 gms of coffee solids per 100 c.c.
(3 ½ oz) of brew, the average being 0.9 to 1 gram
of coffee solids. The strength of brew obtained in normal
brewing lies between 1.1 and 1.4 grams per 100 cc. |
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| General |
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| Spread uniformly the correct weight of
powder in the brewing device, so as to make a uniform
bed for proper extraction. It has been shown that if the
powdered coffee is wetted with water before making the
bed, The extraction is more uniform besides giving a slightly
higher extract. About ½ oz of water will be enough
for every ounce of coffee powder. If more water is used
for wetting, percolation will be affected. |
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| The time of extraction varies with the
grind of powder and the brewing device. Fine the powder
the shorter should be the time of contact; coarse grinds
require longer time of contact. |
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| The time taken with very fine powder in
a filter could vary from 15 Mts. to 1 to 2 hours depending
on the ratio between the weight of powder and the volume
of water and the total quantity of powder used. At lower
ratios and with the use of a larger quantity of powder
disproportionate to the capacity of filter, the extraction
as well as the time of contact are affected. The brew
obtained initially will be stronger than subsequent volumes
and will remain at the bottom. Hence, to get a uniform
brew quality, the brew finally collected should be mixed
before serving. |
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| Number of servings for 100 gms.powder: |
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| Depending upon the strength (Coffee solids
per 100 c.c.) the number of servings may vary from 12
to 16 cups of normal single strength brew. |
